March 2 (Bloomberg) -- A winter storm dropped as much as 9 inches of snow on the New York City area and parts of the Northeast U.S., disrupting travel and slowing commutes.

An additional 4 to 6 inches (10 to 15 centimeters) is forecast as snow makes its way up from the South. Hundreds of flights were canceled at airports in the Northeast, with delays of as much as an hour for remaining flights, and commuter rail lines into New York City were delayed up to 15 minutes.

“The good news is that the snow is going to start to taper off later on this morning in D.C. and Philadelphia and this afternoon in New York,” said Tom Kines, a meteorologist at AccuWeather.com in State College, Pennsylvania.

The snowfall, which began last night in parts of New York City, may reach a record-setting 14 inches (36 centimeters) by noon, said the National Weather Service. Driving would be difficult, the weather service said.

“Persons are urged to stay indoors unless absolutely necessary as travel conditions will be very treacherous until the heavier snow tapers off,” the weather service said in a statement.

Gary Conte, a weather service meteorologist in Upton, New York, called it “a good, old-fashioned snowstorm.” The one-day record for a snowfall in March is 10 inches, set in 1896, he said.

“Obviously, based on our forecast, that is in jeopardy. March is coming in like a lion,” he said.

Snow Moves North

A second band of snow in the Washington-Baltimore area early today is expected to add another 4 to 6 inches to what has already fallen in the New York City area, said Patrick Maloit, meteorologist for the weather service in Upton.

High winds accompanying the snow will cause drifting and unseasonably cold weather, Conte said, with temperatures ranging from 20 degrees Fahrenheit (-6 degrees Celsius) to freezing, 10 degrees to 15 degrees below normal.

“This is not the type of snow that gets melted within 24 to 48 hours,” he said.

In Boston, the Massachusetts Bay Transportation Authority was reporting delays as long as 25 minutes for some commuter rail routes west of the city. Hundreds of flights have been canceled at airports from Washington northward. Dulles International Airport, Reagan National Airport and Baltimore/Washington International Thurgood Marshall Airport all reported as many as 50 flights have been canceled.

More Flights Canceled

At Newark Liberty International, John F. Kennedy International and LaGuardia airports in the New York City area, nearly 1,000 flights were canceled, said Ron Marsico, a spokesman for the Port Authority of New York and New Jersey.

New York City public schools halted classes for 1.1 million students, and Boston, Providence and New Haven along with many of their suburbs closed schools for the day.

In Connecticut, Republican Governor Jodi Rell ordered non- essential state employees to come into work two hours later than normal. Snow was falling at rate as fast as 2 inches an hour in some places.

To contact the reporters on this story: Peter S. Green in New York at psgreen@bloomberg.net; Brian K. Sullivan in Boston at bsullivan10@bloomberg.net.

Last Updated: March 2, 2009 09:14 EST